Armature construction for dynamo-electric machines and process of producing the same



Oct. 28. 1924. 1,513,405

A. D. 'r. LIBBY ARMATURE CONSTRUCTION FOR DYNAMO ELECTRIC MACHINES AND PROCESS OF PRODUCING THE SAME Filed Oct. 30. 1920 INVENTOR Patented Get. 28, 1924.

UNITED STATES PATENT OFFICE.

ALBION D. '1. LIBBY, 0] EAST ORANGE, NEW JERSEY, ASSIGNOB TO BPLITDOBF ELEC- TRICAL COMPANY, OF NEWARK, NEW JERSEY.

ABHATUBE CONSTRUCTION FOB DYNAMO-ELECTBIC MACHINES AND PROCESS OI PRODUCING THE SAME.

Application filed October 30, 1820. Serial No. 420,781.

To all whom it may concern:

Be it known that I, ALBION D. T. LIBBY, a citizen of the United States, residing at East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Armature Constructions for Dynamo-Electric Machines and Processes of Producing the Same, of which the following is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

In the manufacture of motor or dynamo armatures wherein an insulating material is used to support and space apart the commutator bars, it has been necessary to go to 3 a great deal of trouble and expense to properly support, space and insulate thesebars from one another.

In the Borger Patent 1,416,256 issued May 16, 1922, the conductor bars forming the end turns are in general self-supporting, although said application is not limited to such a construction. The object of this in vention is to provide a specific means for supporting the end turns when they are ..ot formed to be self-supporting.

it is another object of this invention to simplify the construction of such an armature.

It is a still further object of this inven tion to provide a process for moulding mate rial about the spaced-apart conductors forming the brush bearing ends.

In the drawings which form part of this specification:

Figure 1 is a view of the moulded end of the armature.

Figure 2 is an end view thereof, the circle shown in broken lines representing the inner edge of the conductor bars.

Figure 3 is a section taken along one of the conductor bars and along the line 3-3 of Figure 1.

Figure 1 is a development of some of the armature conductors.

Figure 5 is a half-sectional view of the armature in its mould, the armature section being taken along the line 5-5 of Figure 1, and the central core being shown in elevation.

Figure 6 is a detail view on an enlar ed scale of one of the members used during the moulding process.

This process is particularly adapted to the construction of an armature in which the laminations and windings are assembled as a unitary structure and the shaft subsequently slipped into position, there being a small clearance between the shaft and the laminations as shown in the Tomlinson Patent 1,262,873 issued April 16, 1918, although it is to be understood that the process is equally adaptable to the type of armature wherein the shaft is keyed to the laminations as is the usual practice.

The armature comprises a magnetic element built u of laminations 1, the laminae being cappe with two fibre washers 2 and and a pair of metallic washers 4 and 5, through which rivets 6 are passed to bind the parts together. The shaft drives the armature by any suitable means. The laminae are slotted as is the usual practice and lined with an insulator 7 such as impregnated paper or fibre and within the slots are laid two superimposed conductor bars 8 and 9 separated by a layer of similarly treated paper or fibre 10.

These conductor bars as shown in Figure 4 each consist of parallel portions 8 and 9 adapted to rest in the upper and lower portions of the slots of the armature respectively, and angularly bent portions 11 which project beyond the armature and which at their lower ends are joined to similar inductor bars 24 of the next succeeding set, the upper angularly bent portions being integral with one another. The upper set of angular bars is insulated from the lower set of angular bars by means of oiled silk 12 as is well understood in the art, all of the con ductors forming a continuous winding. The projecting portions of the bars form cylinrical recesses to carry current into or out of the armature, brushes may hear u on the outer cylindrical surface of one or th of these portions.

In the preferred form of my invention one end of the conductor bars is strengthened and the respective bars are held in place by means of a moulded annular ring 13 of bakelite or equivalent material. This ring on the upper surface merely joins the extreme ends of the bars leaving the brush bearing surfaces openly spaced apart from one another Without any intervening insulation. The ring on the inner cylindrical surface of the conductor bars, enters in the spaces between the angular projecting ends of the lower conductors, though for clarity of illustration, the spaces are left blank 1n Fi re 3.

11 order to mould this ring, the armature is set into a cu shaped mould 14; provided with a central oss 15 which rests against the lower fibre ring 3 and a central core member 16 provided with afireduced end 17 is driven into the center of the armature normally occupied by the shaft. In between the base portion of the bars, or the portion of the bars adjacent the magnetic element are positioned slugs 18 each provlded with an inclined portion 19 adapted to fit between the bars so as to properly space them apart and wholly fill the space between them. Integral with each slug and 1ncl1ned w th respect thereto is a wedge member 20, WhlCll when the slug is in place has an axis parallel to the axis of the armature. The lower surface 21 of the wedge rests in the member 14, the to surface of which is flush with the top 0 the magnetic element. In order to securely retain the various slugs in place, a ring 22 is forced down upon the wedge members. Bakelite or some other suitable compound is then poured in the space between the ring 22 and the core 16 and the whole subjected to pressure by means of a die 23, while under the influence of heat. After the moulding material has cooled, the armature is removed from the mould and the slugs 18 are withdrawn leaving an integral annular ring forming a support for the armature conductor end turns, at the same time leaving an internal annular recess for the shaft bearing.

Although I have chosen to illustrate'my slugs with the inclined portion 19 of a length less than that of the protruding ends of the conductor bars, it can be understood that if it is desired the slugs may be of a length equal to that of thebars in which case the moulded ring will merely fill the space in between the bars of the lower conductors leaving the upper conductors spaced apart throughout their length.

Having thus described my invention, what I claim is:

1. An armature for an electric motor or dynamo, having a magnetic element with conductors disposed in a continuous winding about the periphery thereof, said conductors having their end turns openly spaced apart about the axis of said armature and affording bearing surfaces for brushes to convey current to and from said armature winding and a supporting ring of hard infusible insulating material moulded around and in between the extreme ends of said conductors beyond the brush track.

2. An armature for an electric motor or dynamo including a magnetic core having a continuous windmg consisting of a plurality of layers of conductors arranged about the periphery of said magnetic element and projecting exteriorly beyond the end thereof; said projecting end turns being diagonally arranged and connected together in openly spaced concentric arrangement about the axis of said armature and affording bearing surfaces on the upper layer for brushes to convey current to and from said armature winding and a ring of hard infusible insulating material moulded under the lower layer of conductors and over the ends of both layers and extending between the conductor ends to provide a rigid support for the same.

3. The process of constructing an armature which consists in taking a core of magnetic'material, placing conductors thereon and spacing apart the end turns of said conductors, insert-ing slugs between the conductors at the core ends thereof, locking said slugs in place whereby the end turns may be maintained in spaced relationship, then moulding an insulating material in and around the conductors at their extreme ends and finally turning a surface on the conductor ends for the operation of brushes thereon.

4. The process of constructing an armature which consists in taking a core of magnetic material, placing conductors thereon and spacing apart the end turns of said conductors, inserting the core and conductors in a cup shaped supporting member with the top of the core substantially flush with the upper surface of the member, inserting slugs in between the conductors at their core ends with extensions of slugs resting on the member, forcing a clamp ing ring over conductors to force and hold the slugs in place, then moulding an insulating material in between the conductor and finally turning a surface on the conductors for the operation of brushes thereon.

5. The process of constructing an armature which consists in taking a core of magnetic material, placing conductors thereon and arranging the end turns of the conductors in the form of an annulus around the center line of the core with the said end turns spaced'apart, supporting the armature in a fixture, placing slugs in between the conductors at their core ends leaving an open space near their-free ends, fitting a clamping ring around said slugs to retain them in place, fitting a central mould within the hollow formed by the conductors and spaced from said conductors and then moulding insulating material into the interstices between the spaced apart conductors and between the conductors and the central mould.

In testimony whereof, I aflix my signature.

ALBION D. T. LIBBY. 

